Sürdürülebilir Kalkınma Amaçları

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• MakaleYalnız künye2026/r/gumushane/13852
  Crustal structure and major tectonic features of the South Caspian Basin: Insight from Bouguer gravity data

  Kadirov, Fakhraddin; Maden, Nafiz; Safarov, Rafig; Gahramanov, Murad

  The South Caspian Basin is characterized by high tectonic activity, which resulted in the presence of significant hydrocarbon resources that are currently being exploited. This has led to a surge in research efforts, as the basin's substantial hydrocarbon reserves, coupled with its complex tectonic history, attract considerable scientific interest. This research study aims to contribute to our understanding of the crustal structure of the South Caspian Basin. To achieve this objective, we employed geophysical techniques, with a primary focus on analyzing Bouguer gravity data, power spectrum analysis, and edge detection methods. This comprehensive approach, integrating diverse methodologies, provided substantial advancements in our understanding of the basin's geological framework, with valuable insights into the tectonic processes operating in the region. In the Absheron-Prebalkhan zone, the Moho depth was constrained to an estimated 42 km. The investigation further reveals a constriction of the area towards the east, reaching a depth of 36 km near Prebalkhan and a final depth of 39 km within Prebalkhan itself. The total horizontal gradient technique and the logistic filter were implemented on the gravity data of the study region to figure out faults, geological boundaries, and structural lineaments within the South Caspian Basin.

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• MakaleYalnız künye2025/r/gumushane/12548
  Mantle genesis and crustal contamination in Carboniferous granitoids using U-Th-K concentrations at the Akşar Pluton in the Eastern Pontides, NE Türkiye

  Maden, Nafız; Gücer, Mehmet Ali; Akaryalı, Enver

  New radiogenic heat production (RHP) data are presented for Carboniferous granites outcropping in the Akşar region (Bayburt, NE Turkey) to contribute to ongoing debates on the genetic and lithologic relationship between the Akşar and Gümüşhane plutons, which is the most widely distributed granitic rocks in the region. The scope of this study consists of rocks composed of enriched mantle material metasomatized by fluids from the previously subducted plate. We observed average K value for the Akşar Pluton was found to be 3.09 ± 1.58 %. Additionally, average Th/U and U/Th values of 3.95 ± 1.37 and 0.29 ± 0.10, respectively. The calculated RHP value for the Akşar Pluton was 2.20 ± 0.56 μWm−3. Numerical results suggest that the Carboniferous Akşar pluton's primary magma was the product of mixing lithospheric mantle and mid-to-lower crustal melts because of partial melting, differentiation, and emplacement in the shallow continental magma chamber. The geochemical and petrogenetic characteristics of the Akşar region magmas suggest that crustal contamination occurred at multiple levels, particularly within the lower to middle crust of the plutonic core complex. This complex likely retains geochemical signatures indicative of subducted Paleotethys oceanic lithosphere. These findings provide critical insights into the magmatic evolution of the Eastern Pontides, contributing to a more comprehensive understanding of crust–mantle interactions and the broader geodynamic framework of northeastern Türkiye.

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• MakaleAçık Erişim2022/r/gumushane/14552
  Investigation of natural radionuclide variations and the possible uranium migration by testing with gamma-ray spectrometer: An example from Tuğlu Tepe and Deliler Sites in Şefaatli/Yozgat, Central Anatolia Region, Turkey

  Altundaş, Suna

  The in-situ gamma-ray spectrometry measurements are performed to define and map natural radionuclide variations and the possible uranium migration on the sandstone in the Central Anatolia Region and Deliler sites in Yozgat, Turkey. The concentrations of radionuclide (eU, eTh, K%) and dose rate values were measured totally on 384 points in both areas with a duration of 5 min at each measurement point. The radionuclide ratios (eTh/K, eU/K, and eU/eTh), geochemical indicators (Ume, F parameter and eU-(eTh/3,5) rate) of uranium remobilization in the rocks, and the hazard parameters were calculated and evaluated by using measured data. The separation of uranium-rich or poor areas was made easily and associated with lithological formations by evaluating all the maps produced together. While the highest concentrations of radionuclide, and dose rate values were recorded in the sandstone units under the cover layer that are Eocene neritic limestones, the lowest concentration values and dose rate were measured on siltstone and claystone in the northern part of the Tuğlu Tepe area. At the Deliler study area, the lower anomaly zones are coincide with the soils used for the cultivation of chickpeas consists of loosely cemented sandy clay siltstone, claystone, gravel, sand, silt, and clay whereas the highest concentrations observed in the outcropped sandstone and limestones. It can be seen that the study areas have variable radioactivity levels as a result of both the weathering from the surrounding granitic rocks and the transport and accumulation of sediments through different factors. On sandstones serving as reservoir rock for uranium mineralization in both Tuğlu Tepe and Deliler sites, there is a uranium migration from the granitic rocks towards these masses and sandstones have been enriched by uranium. As a result of the evaluations, it has been seen that the areas showing uranium enrichment originated from migration can be determined very easily by radioactivity measurements, which is a fast, economical and effective method.

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• MakaleYalnız künye2020/r/gumushane/14973
  Determination of geological structures by geophysical and geotechnical techniques in Kırklartepe Dam Site (Turkey)

  Sari, Mahmut; Seren, Aysel; Alemdag, Selcuk

  In foundation research of engineering structures, application of geophysics methods before drilling work allows not only more economical studies but also a more detailed determination of underground sections. Especially in pre-feasibility studies on long tunnel routes, dam sites and lake areas, it has a vital importance in terms of structural safety to determine possible underground buried fault lines, lithology changes, anticlinal-synclinal structures and underground openings. By considering these effective factors, the alluvium/bedrock border and the positions of potential buried faults in the dam site and lake area in the Kırklartepe area of the province of Bayburt in northeastern Turkey were determined by comparison with geophysical and geotechnical methods. First of all, the resistivity of the dam axis location and the change of the Vp wave velocity by depth were determined by comparing the results between geophysical methods of electrical resistivity tomography (ERT) and seismic refraction tomography (SRT), respectively. Afterwards, from the foundation boreholes opened in the dam axis location, joint frequency and the other parameters determined by observations were obtained. With these parameters, 2-dimensional zoning profiles of the dam axis location were formed, and the alluvium-bedrock border and the locations of the buried faults were determined. Two potential faults in the NW-SE direction relative to the location of the dam axis were clearly revealed in the zoning profiles obtained in the ERT and SRT measurements. Additionally, the presence of these faults was determined as a result of examining the separation and joint frequency parameters from the drilling core samples collected from the BH_3 and BH_5 boreholes opened in the investigated area based on changes in the vertical and horizontal directions. In addition to these, in the ERT study, two potential faults other than the determined two were also detected. It was seen in the zoning profiles that these faults corresponded to right under the BH_2 borehole and 60 m SW of the BH_6 drilling. Consequently, in the zoning studies conducted at the examined site, the change in the lithology at the dam axis by depth (alluvium-bedrock border), lateral correlations of boreholes and potential faults were determined. It was recommended for the selected dam axis location to be constructed at a more suitable place in the NW direction in terms of engineering. Furthermore, with this study, it was revealed once again that it is highly essential to use geophysical and geotechnical together in conceptualizing large engineering structure projects.

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• MakaleYalnız künye2015/r/gumushane/12362
  Gamma ray spectrometry for recognition of hydrothermal alteration zones related to a low sulfidation epithermal gold mineralization (eastern Pontides, NE Türkiye)

  Maden, Nafiz; Akaryali, Enver

  This study presents an interpretation of radiospectrometric and magnetic data of Arzular mineralization site, which is one of the best examples for epithermal gold deposits located in the southern zone of the Eastern Pontides (NE Türkiye). Potassium is generally the most useful pathfinder element for gold mineralization zones because of its high level in altered rock surrounding the deposits. Where gold is hosted within quartz veins, typically the vein is low in the radioelements, but the hydrothermally altered host rocks will usually have a distinct radioelement signature useful for exploration. In this study, magnetic, susceptibility and radiospectrometric survey data radiometric signatures associated with the host rocks favorable for the mineralization, enhancing techniques such as the ratio maps as well as potassium (%K), equivalent thorium (eTh ppm) and equivalent uranium (eU ppm) maps were utilized. Our analysis showed that the gold mineralization associated with the alteration is significantly related to increase in potassium, due to adularia, a low T K-feldspar, and decreases in uranium and thorium due to the hydrothermal alteration and magmatic intrusion processes during the regional tectonic activities.

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